Update to upstream 6.7.0 version
    
        - Update to upstream 6.7.0 version.
        - Update the URL.
        - Droped the patch 0001-Update-version-to-reflect-6.5.6.patch.
        - Remove comments that had macros in them, making rpm spit out warning
          during the build.
        - Add a patch to force "make docs" to build the documentation, even
          though there is a directory named 'docs'.
        - Add asciidoc as a build dependency.  This is useful because the new
          manpage generation mecanism introduced by upstream needs it.
        - 'make docs' is is the new way to generate the man pages.
        - There is now a new offlineimapui.7 man page.
    
    Signed-off-by: Dodji Seketeli <dodji@seketeli.org>